TheSkySearchers

With several new-moon clear nights forecast this week, I thought it would be a good idea to clear the snow off the dome.
That turned out to be harder than it looked. Not only is the top of the dome impossible to reach, but the recent cycle of storms started with an ice storm, so the base layer was frozen solid. I managed to chip away enough snow and ice to rotate the dome, with manual assistance. (The rotation motor was trying, but I had to haul the dome around by hand to keep it moving.) That allowed my to reach all azimuths of the dome from the front deck. I paid extra attention to the shutter track, clearing as much of the snow and ice as possible from it.

So the final step was to try the shutter. It has a very powerful geared DC motor, so I was optimistic that it could break the remaining ice free. Nope! The motor is indeed powerful, though: the aircraft-grade stainless steel cable snapped! I guess the ice was stronger.

So, with no way to open the shutter until I can do repairs, the observatory is out of commission for a while.

Ugh that's a bitter pill to swallow.

There is no way to warm things up to melt the ice and snow?

Very annoying and disappointing; sorry that happened, Kathy. Foiled again by water - as clouds or as ice, it has its own way.

Ah thats a bummer , but another lesson learnt I suppose. Everything will be a bit more fragile in the cold as well. Might be time to snuggle up with a book. I've never had to live with those extremes. Good luck . Phill

For fast snow removal.

How did I know it involved a flame thrower before I even clicked the link

Bummer! I wonder if it is possible to install some sort of heating elements to defrost the dome as needed.

We are supposed to have a thaw on the weekend. If I help it out with a portable heater, it might melt the ice.

Shame Kathy. When I read the title though, I was thinking something serious!

You certainly have an impressive setup under that snow. Beautiful, beautiful location!

Jim

Wow, that's cool! It looks like a giant "Shave Ice" you'd get out here on the islands.

I hope it clears easily enough so you don't get a coronary!

Cheers,
JT

Bummer.

I used bolt cutters to clip a section of the broken cable as a sample. I think they have cable like that in Home Depot. I'll go have a look this afternoon.

While I was out there, I checked for damage at the attachment points for the cable, the pulleys, and the motor. All are fine. Who knew that the weakest link in that system would be aircraft grade stainless steel cable?

That is unfortunate, Kathy. I'm glad it sounds like it won't have you out of commission too long!

Bob

Did the cable break or the swage fittings? Typically they fail at the fittings.

UlteriorModem wrote: ↑Wed Jan 22, 2020 6:36 pm Did the cable break or the swage fittings? Typically they fail at the fittings.

It was the cable that broke, right at the winch. I would have expected the clamp that holds the end of the cable would have let go first, but no it was the cable itself. I just got back from buying some replacement cable. The rated strength is 95 lbs, so it's not ultra-strong. Probably just as well that it will fail before the HDPE of the dome structure itself. That would be expensive.

Think of it as sort of a fuse to protect the other pieces

Hope you get back up and running soon.

UlteriorModem wrote: ↑Wed Jan 22, 2020 8:56 pm Think of it as sort of a fuse to protect the other pieces

Hope you get back up and running soon.

I don't plan to repeat the exercise, but if it does happen again, I hope the cable fails the same direction. It broke at the winch, so the free end whipped towards the base of the shutter, away from my computer desk. If it were to break at the shutter end, the free end would whip towards me. Hopefully, the tension vector would take it high enough to clear my head, but...

I'll bet you nearly pooped your breeches and jumped a foot when that happened!

UlteriorModem wrote: ↑Wed Jan 22, 2020 9:15 pm I'll bet you nearly pooped your breeches and jumped a foot when that happened!

Too busy! I heard the motor starting to strain, so I was moving the mouse to the emergency stop button when It let go. It all happened too fast for anything else.

Maybe you should wear safety glasses